Even in absence of pollinating agents seed-setting is assured in

Commellina benghalensis or kankauoa bears aerial, chasmogamous (stigma and anthers exposed to pollinating agents), insect pollinated flowers and underground cleistogamous flowers. Cleistogamous flowers are bisexual flowers which never open, i.e., always remain closed. In such flowers the anthers and stigma lie very close to each other. When anthers dehisce in the flower buds, pollen grains come in contact with the stigma of the same flower, i.e., autogamy occurs. So, these flowers produce assured seed set, even in the absence of pollinators.